The field of the invention is power steering apparatus for vehicles, especially those whose steered wheels are turned by one or more hydraulic actuators, and that are primarily for off-highway applications such as agriculture or earth moving. Many prior power steering systems for use in such vehicles have hydraulic equipment such as hoses and/or mechanical linkages entering into the cab of the vehicle. Some prior systems exhibit drift, requiring the driver to continue turning the steering wheel slowly in order to drive straight.